Segmented thread coupling



' United States Patent [72]. Inventor Jerald V. Dunlap P.O. Box 1541, Santa Monica, California 90406 [21] App1.No. 753,299

[22] Filed Aug. 16, 1968 [45] Patented Nov. 17, 1970 [54] SEGMENTED THREAD COUPLING 5 Claims, 6 Drawing Figs.

85/1; 287/125 511 1111.01. ..Fl6115/00 so] FleldofSearch 285/391,

355, 332.4,333, 334; 85/1 lnquired, 32 lnquired; 287/62, 117, 125

ABSTRACT: Quick connect and disconnect threaded couplings for tire hoses are provided with segmented thread means for enabling connection and disconnection to take place with less than one full turn of the coupling. The coupling includes a first member having a cylindrical exterior forward portion with circumferentially spaced external thread segment means defining external sectors free of threads, and, a second member having a cylindrical interior surface portion with circumferentially spaced internal thread segment means defining internal sectors free of threads. Cooperating thread abutting means are provided on the members such that insertion of the forward portion of the one member into the interior surface portion of the other can take place with any one, of the external thread segment means being received in anyone of the internal sectors with complete assurance that the external and internal thread segment means will be in proper axial alignment and positions relative to each other for threading together upon rotation of one member relative to the other.

Patented Nov. 17, 1970 3,540,762

INVENTOR JERALD V. DUNLAP FIG. 6 BY I BACKGROUND OF THE INVENTION In fighting fires, it is-necessary to effect very rapid connections and disconnections between lengths of fire hose as well as to hydrants or other sources of water supply. Normally such couplings for the various lengths of hose takes the form of a threaded male member and a swivelly-formed threaded female portion on the opposed ends of the hose to be connected or disconnected. In the case ofa major fire, several different fire departments may participate and in this respect, it is not uncommon to couple hose sections of one fire department with those ofanother.

To assure that all types of equipment from various different fire departments throughout the entire country will be compatible, there has been established the National Fire Protection Association Standard for Fire Hose Coupling Screw Threads. These standards,-at present, require a single lead screw thread of a given pitch and a given number of turns for various classes of hose'determined by the hose diameter. As a consequence ofthis standard. fire hose couplings are compatible among various different firc'departments. There is still involved, however, aconsiderahle waste in time in actually effecting various connections and disconnections of the hose lengths.

'In an effort to solve the foregoing problem, different types of quick-connect" and quick-disconnect" couplings have been proposed. Certain types of these couplings principally manufactured in foreign countries involve simple bayonet type hook and slots so that less than a full turnis necessary to effect a desired coupling. These devices however are totally incompatible with present fire fighting equipment and the standards set forth by the National Fire Protection Association and therefore, from the standpoint of practicality, are unusable in this country. Other types of proposed prior art couplings for enabling very rapidconnection and disconnection of fire hoses contemplates the use of segmented threads; that is, thread segments extending only partially circumreferred to with respect to prior art type segmented thread couplings are overcome.

More particularly, the coupling of the present invention comprises a first member including a cylindrical exterior forward portion having a circumferentially-spaced external thread segment means defining external sectors free of threads, and a second member including a cylindrical interior surface portion for receiving the forward portion of the first member and having circumferentially-spaced internal thread segments defining internal-sectors free of threads. Cooperating thread abutting means are provided and positioned such that insertion of the forward portion into the interior surface portion can take place with any one ofthe external thread segment means being received in any one of the internal sectors with the external and internal thread segment means in proper axial alignment and positions relative to each other for threading' together upon rotation of'onc member relative to the other.

The thread segment means on the members are each defined by a singlelead thread with circumferentiaIly-spaced sectors free of threads to leave circumferentialIy-spuced thread segment means. The position of the single, lead thread possible positions without fear ofjamming or cross threading.

Finally, there is included stop means in the second member in a position'to hlock relative rotation ofthe members when the external thread segment means have respectively-been completely threaded'to the'internal thread segment means-and the initial and terminal points of the external and internal secfercntially aboutthe coupling are provided to leave sectors free of threads; With this arrangement. the members may be axially positioned together with the thread segments of one member being received within the sectors free of threads in the other member and thereafter only a partial turn is necessary to tighten the threads together.

Three major problems have arisen with such types of segmented thread couplings. First, when utilizing thread segments circumferentially separated by sectorsfree of threads, 7

the manner in which the couplings may initially be axially moved together with certain thread segments received in certain sectors free of threads is ambiguous and there is no assurance that proper threading can be completed for all possible positions of thread segments in the sectors free of threads. In other words, in several of the possible positions, the coupling members wiIItend to cock ortilt relative to each other resulting in cross threading. Second, there has been lacking any assurance that even when properly positioned for threading, rotation of the members will be checked or stopped when the threads are completely engaged. Without a suitable stop means, the threaded segments may be only :partially BRIEF SUMMARY OF THE PRESENT INVENTION With the foregoing considerations in mind, the present invention comprises an improved segmented thread type of coupling for fire hoses wherein the problems heretofore tors are aligned..The integrity of the connection is thus ass'ured and in all instances, the couplings can .be effected with less than a full turn of one member relative to the other.

. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 4 is an end elevational view of the other of the mem-' bers ofFIG. I looking in the direction of the arrow 4;'

FIG. 5 is a flat layout of the internal thread segment means ofthe member of FIG. 4; and

.FIG.,6is a cross section of the members illustrated in FIG. I in coupled'relationship.

. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring first to FIG. I there is shown a first coupling member 10 includinga tailpiece portion I] connected to one end of a length of fire hose 12. This member includes acylindrical exterior forward portion 13 having a single lead external thread only on the forward portion with circumferentiallyspaced external sectors free of threads to leave circumferentiaIly-spa'ced external thread segment means indicated at l4, l5, and 16. The sector portions free of threads are indicated at 17, I8, and I9 and In this preferred embodiment there are provided three such sectors equally circumferentiaIly-spaced and subtending substantially equal angles.

A first thread abutting means is provided in the form of a continuation of the rearward most external thread of one of the external thread segment means as indicated at 20 such that 'a thread abutment is provided-in at least oneef the sectors in helical alignment with the external thread.

Referring now to the second coupling member illustrated in FIG. 1, this coupling is indicated generally by the numeral 21 and includes a tailpiece portion 22 connected to the end of a hose length 23. A swivel mounting 24 is coupled to the tailpiece 22 and has a cylindrical interior surface portion for receiving the forward portion of the first member 10. This interior surface portion includes a single lead internal thread with circumferentiallyspaced internal sectors free of threads to leave circumferentially-spaced internal thread segment means 25, 26, and 27. The internal sectors are indicated at 28, 29, and 30 and are three in number and equally circumferentially-spaced and subtend equal angles.

A second thread abutting means takes the form of a continuation of the rearward most internal thread as indicated at 31 to define an abutting means in at least one of the sectors which is helieally aligned with the internal thread.

The circumferential extent or angle subtended by the external thread segment means and internal thread segment means corresponds substantially to the angle subtended by the sectors or portion free of threads so that the forward portion 13 of the coupling may be received within the swivel 24 ofthe coupling 21 with any one of the external thread segment means 14, 15, or 16 receivable in any one of the internal sectors 28,29, or 30. The respective thread abutting means in the form of the rearwardly disposed continuous threads 20 and 31 respectively for the members 10 and 21 are such that regardless of which external thread segment means is received in which internal sector, abutment of the forwardmost threads on internal and external thread segment means with the thread abutting means occurs on both sides of all diameters through the axis of the members when the same are assembled together. As a consequence, the respective external and internal thread segment means are in proper axial alignment and positions relative to each other for threading together upon rotation ofone member relative to the other.

In one of the possible three positions, only a one-sixth turn is necessary to effect complete threading. In a second possible position, a halfturn is necessary, and in the third possible position five-sixths of a turn is required. In every instance, however, less than one complete turn is necessary to assure proper threaded engagement between the couplings.

Theforegoing arrangement as well as further features and advantages of the coupling of this invention will be better understood by now referring to FIGS. 2 through 6.

Referring first to .FIG. 2 wherein the end of the first coupling member 10 of FIG. 1 is shown in plan, the substantially equal circumferential spacing and extent of the external thread segments 14, 15 and 16 relative to the external sectors 17, 18, and 19 is clear. Further, it will be noted that the first thread abutment means in the form of the continuous rearward thread 20 extends into all of the three sectors 17, 18, and 19, although such is not essential to the invention.

In the layout of the external thread segment means as illus trated in FIG. 3, it will be noted that the thread abutment means in the form of the continuous thread 20 initiates as a continuation of the rearward most thread of the thread segment means 14. This thread segment means has a forward most thread which is in the second forward most axial position of the forward most threads of the remaining two external thread segment means 16 and 15.

Referring now to FIG. 4 the corresponding circumferential extent of the internal thread segment means 25, 26, and 27 relative to the internal sectors 28, 29, and 30 will be evident. As in the case of the first thread abutment means 20 for the coupling 10 of FIGS. 2 and 3, the second thread abutment means for the member 21 extends over a complete turn to pass through the three internal sectors as indicated at 31.

It will be also noted in FIG. 4 that the second coupling member 21 includes an internal ring 32 surrounded by a sealing gasket 33. The ring 32 has its forward surface slightly below the annular seal 33 such that when the front surface of the forward portion 13 of the member 10 of FIG. 2 abuts gasket 33 some compression will take place before this forward end seats on the ring 32. The axial position of the ring 32 relative to the forward end of the forward portion 13 of the member 10 is such that full surface engagement will take place only when the external thread segment means l4, l5, and 16 of FIG. 3 are fully threaded with the internal thread segment means 26, 27, and 25 respectively with the initial and terminal points of the external and internal sectors aligned. The ring 32 thus functions as a stop means as will become more fully apparent when the operation of the overall coupling is described.

In FIG. 5, it will be noted that the second thread abutment means in the form of a continuous thread 31 initiates at that internal thread segment means 26 having a forward most thread which is in the second forward most axial position of the'forward most threads of the remaininginternnl thread segment means 25 and 27.

The number ofthrcad segments in each external thread segment means l4, l5, and 16 of FIG. 3 is equal respectively to the number of thread segments in each internal thread segment means 26, 27, and 25 of FIG. 5.

Referring nowto the assembled view of FIG. 6, the manner in which the gasket 33 surrounds the stop ring .32 and protrudes slightly forward thereof to effect a sealing engagement against the forward end ofthe forward portion 13 will be clear. It will also be noted that the tailpiece 22 includes a pair of zero pitch threads'34 for engagement with corresponding threads on the swivel 24 such that rotation ofthe swivel 24 can take place relative to the tailpiece 22 without any axial movement thereof.

OPERATION illustrations of FIGS. 3 and 5 together, visualize the right end of threads 16in FIG. 3 as curved downwardly into the plane of the drawing and upwardly to terminate at the left to present a convex view of the sectors 19, 17, and 18. In FIG. 5, visualize the right end of the sector 30 as curved upwardly out of the plane of the drawing and downwardly to terminate to the left to present a concave view of the sectors 28, 29, and 30.

Next, if the member 10 is now viewed from the bottom and rotated clockwise one-fifth ofa turn, the threads will be positioned as shown in FIG. 2, the reference lines L1 denoting the center of threads 14. If the member 21 of FIG. 5 is viewed from above, it will appear as in FIG. 4, the reference lines L2 denoting the center of threads 26.

In these positions, if the members 10 and 21 are brought axially together, the thread segment means 14, 15, and 16 will be respectively received in sectors 30, 29, and 28. The forward most threads ofthe external thread segment means l4, l5, and 16 will all abut against the second thread abutment means in the form ofa continuous thread 31 and because of the helical alignment of this continuous thread 31 with the thread seg-. ment means, it will be clear that axial alignment will be maintained.

In addition, when the member of FIG. 3 is brought down into engagement with the member of FIG. 5, the forwardmost threads on the respective internal thread segment means 25, 26, and 27 will pass within the external sectors l9, l8, and 17 respectively and will abut against the first thread abutment meansin the form ofthe continuous external thread 20. Again because of the helical alignment of this continuous thread 20 with the thread of the external thread segment means, the members will still be in axial alignment.

'In the foregoing position as described, only a one-sixth turn is necessary to bring the respective thread segment means into complete threaded engagement at which time the forward end of the forward portion 13 will abut against the'stop ring 32 described in FIG. 6 after effecting a proper seal on the annular sealing gasket 33. It will be understood, of course, that the one-sixth turn necessary is a relative threading such that the same is actually effected by rotating the swivel 24 of FIG. 6 one-sixth ofa turn.

Uncoupling of the two members is quickly accomplished by simply rotating the swivel 24 in an opposite direction for onesixth ofa turn and then moving the members axially apart.

Assume now that the first and second members are positioned together such that the external thread segment means 14 is received in the internal sector 29 (with reference again to FIGS. 2 and 4). In this case, the external thread segment means 15 will be received in the internal sector 28 and the external thread segment means 16 will be received in the internal sector 30. Thread abutment will take place between the forwardmost thread on the external thread segment means 14 and the continuous thread 31 in the internal sector 29. Simultaneously, thread abutment will take place between the forwardmost thread of the internal thread segment means 25 and the continuous thread 20 in the sector 18. It will now require a relative rotation of three-sixths (one-half) of a turn to effect complete threaded engagement since in the axial position I described, the members are axially intermediate their closest and furthest positions.

The third possible position would result when the external thread segment means 14 are received in the internal sector 28, the external thread segment means 15 received in the internal sector 30, and the external thread segment means 16 received in the internal sector 29. in this case the forwardmost thread on the external thread segment means 16will abut against thecontinuous thread 31 in the internal sector 29, while the forwardmost thread on the internal thread segment means will abut against the continuous thread 20in the sector 17. Again the members will be in axial alignment but in this case five-sixths of a relative rotation must take place to effect complete threading.

It will be understood from the foregoing that because of the fact that the first and second thread abutting means constitute rearward helical, continuations of the rearwardmost external and internal threads of given ones of the external and internal thread segment means, abutment of the forwardmost threads on internal and external thread segment means occurs on both sides of all diameters through the axis of the'rnembe'rs regardless of the three possible manners of insertion of the forward portion of the first member into the second member. Therefore, cocking 0r tilting of one member relative to the other which could result in cross threading is wholly avoided.

From the foregoing description, it will be evident that the present invention has provided a greatly improved segmented type thread coupling wherein the deficiencies characterizing certain prior art segmented type couplings have been completely overcome. ltshould be understoodthat in addition to the features minimizing risk of cross threading as described, the single lead thread from which the thread segment means are formed complies with the standard-set forth by the National Fire Protection Association so that the present couplings are fully compatible with conventional screw couplings presently in operation.

Iclaim;

l. A coupling comprising:

a. a first member having a cylindrical exterior forward portion,

1. said forward portion having external thread means consisting solely of a single lead external thread with circumferentially-spaced external sectors free of threads to leave circumferentially-spaced external thread segmentmeans;"and

2. first thread abuttingmeans in the rearward portion of at least one of said external sectors constituting effectively a helically rearward continuation of the rearward most external thread of a given one of said external thread. segment means;

b. a second member having a cylindrical interior surface portion for receiving said forward portion of said-first s b n -I. said interior surface portion having internal thread means consisting solely of a single lead internal thread with circu-mferentially-spaced internal sectors free of threads to leave circumferentially-spaced internal thread segment means; and.

2. second thread abutting means in the rearward portion of at least one of said internal sectors constituting effectively a helically rearward continuation of the rearwardmost internal thread ofa given one of said internal thread segment means. whereby insertion of said forward portion into said interior surface portion can take place with any one of said external thread segment means being received in any one of said internal sectors, the forward most threads on internal and external thread segment means abutting said first and second thread abutting means respectively on both sides of all diameters through the axis of said members toprevent axial angular misalignment ofthe members and thereby positioning the internal and external thread segment means in proper axial alignment in every engageabie position relative to each other for threading together upon rotation of one member relative to the other.

2. The subject matter of claim 1, in which said external and internal circumferentially-spaced sectors are each three in number and are substantially equally circumferentially-spaced and define substantially equal subtended angles, respectively on said first and second members, the circumferential extent of said external and internal thread segment means corresponding substantially to the circumferential extent of said sectors;

3. The subject matter-of claim 1, in which the number of thread segments in each of said external thread segment in each of said internal thread segment means.

4. The subject matter of claim 1, in which said external and internal circumferentially-spaced sectors are substantially equally 'circumferentially' spaced and define substantially equal subtended angles, respectively on said first and second members, the circumferential extent of said external and internal thread segment means corresponding substantially to the circumferential extent of said sectors; and in whieh said given one of said external thread segment means is that thread segment means whose forwardmost thread is the second forwardmost thread of the external thread segment means. said given one of said internal thread segment means being that thread segment means whose forwardmost thread is the second forwardmost thread of the internal thread segment means.

5. The subject matter of claim 1, including stop means in said second member positioned rearwardly of said second thread abutting means in a position to block further relative rotation of said members when said external thread segment means have respectively been completely threaded to said in-.

points of said external and internal sectors are aligned. 

